The key to storing soybeans is drying and low temperature, and reducing the water content of soybeans is the most important thing for safe storage of soybeans. Generally, soybeans are stored for a long time in summer, and the moisture content in North China is controlled within 12%. When the moisture content of soybean is high, it can be precipitated by sun exposure, but it is best to spread it at low temperature to avoid affecting the quality.
1, storage characteristics of soybean
Soybean has strong hygroscopicity and is prone to mildew. Soybean seed coat is thin, germination hole is large, and its moisture absorption ability is stronger than that of wheat and corn. After moisture absorption and moisture regain, soybean expands in volume and is prone to mildew. At first, the beans were soft, the seed coat was gray and white, and there was a slight odor. Then the beans swell and deform, the navel turns red, colonies appear in the broken grains, and the quality deteriorates sharply.
Soybeans tend to turn red when they are oily. After high temperature storage, two cotyledons often turn red from navel, and then the red color of cotyledons deepens and expands, which leads to serious oil soaking, and high temperature and high humidity also reduce the germination ability of soybeans. After soybean oil turns red, the oil yield decreases, the color of soybean oil deepens, tofu tastes sour and soybean milk turns red.
2, soybean storage method
● If the harvest is large, it can only be put into storage after fumigation with chemical agents. Dry, cool and ventilated houses should be used as warehouses, and all gaps should be sealed. Apply with 20% lime water to kill eggs and adults. The stored beans should not touch the ground, and should be covered with linoleum and plastic film to prevent moisture. Newly-harvested soybeans have a post-ripening effect, and their physiological activities are relatively vigorous, and damp heat is easy to accumulate in the body. Therefore, it is necessary to strengthen ventilation, distribute damp heat in time, and prevent fever and mildew. In order to meet the requirements of safe storage, it is best to blow or turn over the warehouse about 25 days after storage, and remove impurities once in combination with screening to improve storage stability.
● If the harvest is small, you can put it in a container such as a crock or urn, and put some quicklime at the bottom of the crock or urn to absorb water. Don't fill the container too full. Leave a certain space to ensure that the seeds breathe weakly. After the beans are packed, they should be sealed with plastic film, and then covered with toilet paper and wood. Beans for seed preservation are opened before sowing and sown in the sun 1 ~ 2 days later.
3. Preventive measures
The moisture content of soybeans should be strictly controlled during storage, and the moisture content of soybeans during long-term storage should not exceed 12%. After harvesting, soybeans should be fully dried on pods before threshing. After storage, soybeans with high moisture content can be exposed to the sun, but they must be spread and cooled before they can be put into storage. The storage of soybeans should be ventilated in time, and the moisture between soybeans in the new warehouse is uneven. Coupled with the after-ripening effect of soybeans, damp heat in the pile is easy to accumulate, causing fever and mildew. Therefore, it is necessary to ventilate in time, dissipate heat and eliminate dampness. The effect of low temperature sealed storage is good. After winter, it is necessary to strengthen ventilation and cool down. Before spring, it is generally safe to spend the summer with a gland or plastic film sealed storage.